Alignment specs?

[seedling]

Sorry man no offense taken. I probably read a little to far into your use of the word "misconception" lol.

The death wobble is no joke. Glad you got it sorted out. It can be very dangerous just as you described.

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Thanks! That jeep only had 36's on it at the time. But, I could literally see them (outside the fender flares) flopping uncontrollably back and forth. It was so bad that by the time I got it home (only 12-15 miles) that the hard rubber cushions on the shocks was totally destroyed! Scary!!

Sorry man, I'm just always trying to learn / figure stuff out about these cars. And I have so so much left to learn! So would you suggest that 87 grey T attempt to take some of that caster out??

 

[achalmersman]

Thanks! That jeep only had 36's on it at the time. But, I could literally see them (outside the fender flares) flopping uncontrollably back and forth. It was so bad that by the time I got it home (only 12-15 miles) that the hard rubber cushions on the shocks was totally destroyed! Scary!!

Sorry man, I'm just always trying to learn / figure stuff out about these cars. And I have so so much left to learn! So would you suggest that 87 grey T attempt to take some of that caster out??

Its up for his opinion. Personally if it were my car I would drive it and see how it handled. As charlief1 said the camber could be closer to 0 but since these cars dont have wide tires it probably will wear fine. If it drives straight, doesnt drift, steering wheel is straight, and no bump steer I would leave it as is. Personally I like high caster but the feel is an opinionated subject. He may decide he doesnt like that tight feel /more steering effort required. Its all preference as long as the basics are covered. Many late model sporty cars have caster that high. Its one of the things that makes them feel really nice in my opinion.

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[seedling]

Its up for his opinion. Personally if it were my car I would drive it and see how it handled. As charlief1 said the camber could be closer to 0 but since these cars dont have wide tires it probably will wear fine. If it drives straight, doesnt drift, steering wheel is straight, and no bump steer I would leave it as is. Personally I like high caster but the feel is an opinionated subject. He may decide he doesnt like that tight feel /more steering effort required. Its all preference as long as the basics are covered. Many late model sporty cars have caster that high. Its one of the things that makes them feel really nice in my opinion.

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Yeah I didn't see charlief1's post until after I posted mine. Thanks that's kind of what i figured. Is it true that the only way to get that much caster in these cars is by adding aftermarket arms?

 

[achalmersman]

Yeah I didn't see charlief1's post until after I posted mine. Thanks that's kind of what i figured. Is it true that the only way to get that much caster in these cars is by adding aftermarket arms?

I believe so. I personally have not modified mine yet but when I do I will be setting the caster higher than factory spec and probably will be using tubular arms and coil overs. I dont have first hand experience with modifying these so hopefully charlief1 will step back in. There may be offset ball joints available I'm not sure. He will know though.

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[87 Grey T]

So with what im gathering here is pretty much that my caster #'s arent really a problem until I get out to drive it more and possibly notice some abnormal tire wear (well not necessarily a problem but a side effect). Forget to mention the car has Baer bumpsteer correction kit. There are no shims that were put in between the Arm shaft to frame bolts. Maybe that could be why the caster is at that number so they could keep the camber a bit negative. I remember the tech saying something about there had to be at least 14 threads showing on the arm to be safe.

 

[Toby_Goodmk]

Caster being set at 5* negative is kicking the wheel back towards you in the drivers, passengers seat. This helps with high speed handling. Think of it as a grocery cart front wheel. When you run tall ball joints this is what you are trying to achieve...negative caster. As for the camber measurement, the more negative the better the car will handle in aggressive turning higher speed situations. Next time you look at the back tires on an x5 BMW or 730 series look at the rear wheel tilt, it calls for -3* camber...all for the handling aspect. On a rear wheel drive car, you want a .25* degree toe in. Think of toe in as point your feet IN together at your toes...this is your tires being toe in, reverse your feet, toe out!. Reason you want some toe in, is for when the car accelerates the rear tires push the front wheels toe out. Toe in - helps you achieve 0 toe angle.

My car has a complete setup UMI/Viking control coil over setup

I use the taller ball joints in the uppers.

I use these figures which I have set at my align shop to my liking

.5* toe in
-1.75 Camber
-5.5 Caster

Steers like a mofo, return of the steering wheel when making a turn is aggressive. Camber angle being negative makes the car have a better contact path, when pushing the speed in a corner...its fun shit. Toe angle being set in a little more than normal lets me push the crap out of the rear making the front stay close to 0 toe. I have a little more wear that normal from the negative camber, I need to stay up on my tire rotations, but the handling is next to none, close to being a road course car.

 

[achalmersman]

Caster being set at 5* negative is kicking the wheel back towards you in the drivers, passengers seat. This helps with high speed handling. Think of it as a grocery cart front wheel. When you run tall ball joints this is what you are trying to achieve...negative caster. As for the camber measurement, the more negative the better the car will handle in aggressive turning higher speed situations. Next time you look at the back tires on an x5 BMW or 730 series look at the rear wheel tilt, it calls for -3* camber...all for the handling aspect. On a rear wheel drive car, you want a .25* degree toe in. Think of toe in as point your feet IN together at your toes...this is your tires being toe in, reverse your feet, toe out!. Reason you want some toe in, is for when the car accelerates the rear tires push the front wheels toe out. Toe in - helps you achieve 0 toe angle.

My car has a complete setup UMI/Viking control coil over setup

I use the taller ball joints in the uppers.

I use these figures which I have set at my align shop to my liking

.5* toe in
-1.75 Camber
-5.5 Caster

Steers like a mofo, return of the steering wheel when making a turn is aggressive. Camber angle being negative makes the car have a better contact path, when pushing the speed in a corner...its fun shit. Toe angle being set in a little more than normal lets me push the crap out of the rear making the front stay close to 0 toe. I have a little more wear that normal from the negative camber, I need to stay up on my tire rotations, but the handling is next to none, close to being a road course car.

Not to be argumentive, but there is some missimformation here. First off your mistaken your caster is not negative its positive. If it were negative it would handle like crap. Ever tried steering at 20 mph in reverse? That would be experiencing negative caster. Second, unless theres a model I'm not familiar with BMWs dont run -3° camber. I looked up a few x5s just to make sure I was right before posting. More like half that amount. If Im wrong please reference an exact year, model and suspension option please. Even if it were true I personally would never recommend camber that high on one of these cars unless maybe the user was using it for some roadcourse track racing which he hasnt posted saying he is and even then I would think -3° was high but thats not an area I have a lot of experience with. With your camber and toe suggestions on a typical GN i would expect the user to be pissing money away on tires. Too much negative camber and too much total toe. Half a degree is too high in my opinion. Spec is positive .10° plus or minus .20° although I personally wouldn't recommend going negative. If it works for you great but those measurements should hardly be used as a general recomendation for one of these cars unless there are some unmentioned specific reasons or you like wearing tires prematurely.

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[87 Grey T]

 

[87 Grey T]

Umi specs:

 

[seedling]

Umi specs:View attachment 279224

Wow! So according to UMI suggested spec it looks like you are right at it with most everything. And closer to competition spec on your caster! That's awesome! Time to carve some corners now!!

 

[Toby_Goodmk]

Yes positive caster...towards you..got mixed around.

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[charlief1]

What most don't understand is Steering Axis Inclination (SAI). This has to do with the Ackerman effect effect that is in most vehicles. When one wheel turns the other wheel turns at a different angle. The higher the caster the more the opposite wheel has an angle to it so it sits (rides) on the edge. This causes the edge wear that can happen when you have a high caster.

 

[seedling]

What most don't understand is Steering Axis Inclination (SAI). This has to do with the Ackerman effect effect that is in most vehicles. When one wheel turns the other wheel turns at a different angle. The higher the caster the more the opposite wheel has an angle to it so it sits (rides) on the edge. This causes the edge wear that can happen when you have a high caster.

Point well stated!

I stand corrected, as i forgot about the axis in the Ackerman effect (most of us only think of it in terms of being scrub radius with left wheel turning tighter than right). And that would be a direct effect of caster, my apologies!

Wouldn't this also mean that the left front tire would show the most wear, or no?

Thanks!

 

[charlief1]

Point well stated!

I stand corrected, as i forgot about the axis in the Ackerman effect (most of us only think of it in terms of being scrub radius with left wheel turning tighter than right). And that would be a direct effect of caster, my apologies!

Wouldn't this also mean that the left front tire would show the most wear, or no?

Thanks!

The ackerman effect has nothing to do with scrub. Scrub is caused by independent suspension moving up and down. When the front suspension came out the upper and lower arms were equal length. This cause the tire to move in and out causing "scrub" issues. With equal length arms the tires move in and out as the suspension went over the road. The arms kept the tires in a 0 camber position but would move parallel and in and out, causing scrub wear issues.

 

[87 Grey T]

Well the car seems to drive and turn pretty well. I don't wanna push it to hard without a front swaybar on. A swaybar braket bolt broke off in the frame so ill be kinda taking it easy until I can get that bolt out. Thanks everyone for the helpful info.

 

[seedling]

Car looks great man! Go drill that bolt out and carve some corners with that puppy! Very nice looking car!!


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[87 Grey T]

Thank you sir! It took alot linger tha expected but now all the brakes and suspension are finally done

Car looks great man! Go drill that bolt out and carve some corners with that puppy! Very nice looking car!!


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